Dual-source locomotive and power system switching method and device thereof

Abstract

The application provides a double-source locomotive and a power system switching method and device thereof. The power system switching method of the double-source locomotive comprises the following steps: when a first power supply mode switching signal is detected, A1, adjusting a first converter output voltage to a first voltage V1; A2, closing a second switch unit, starting an internal combustion power supply device, until a second converter output voltage reaches a second voltage V2 and an output current reaches a preset current threshold IA; V2>V1; A3, exiting a catenary power supply mode, so as to independently supply power by the internal combustion power supply device; when a second power supply mode switching signal is detected, B1, controlling the internal combustion power supply device until the second converter output voltage reaches the second voltage V2; B2, connecting a power supply line corresponding to the catenary power supply mode until a first converter output voltage reaches a third voltage V3; V3>V2; B3, exiting the internal combustion power supply mode, so as to independently supply power by the catenary.

Description

Technical Field

[0001] This invention relates to a method and apparatus for switching a dual-source locomotive power system, which is particularly applicable to rail locomotives and rolling stock, and power-centralized EMUs. Background Technology

[0002] With the continuous development of rail transit, electrified railways have gradually become more widespread, but some remote areas and branch lines have not yet achieved railway electrification. When locomotives cross between electrified and non-electrified railway lines, they can only be pulled by different types of locomotives, which has a significant impact on railway transportation efficiency. Meanwhile, the country has accelerated the research and development of multi-source braking locomotives. Due to the limitations of battery life, integrated electric and diesel dual-source locomotives have emerged. Achieving seamless and smooth switching of power supply modes and full utilization of energy in integrated electric dual-source locomotives is an urgent problem to be solved. Summary of the Invention

[0003] The problem to be solved by this invention is how to achieve seamless and smooth switching of the power supply mode of a dual-source locomotive with integrated internal power, and provides a method for switching the power system of a dual-source locomotive.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for switching the power system of a dual-source locomotive, wherein the dual-source locomotive has a power receiving device, a diesel power supply device, and an intermediate DC circuit; the contact wire is electrically connected to the intermediate DC circuit in sequence through the power receiving device, a first switching unit, and a first converter; the diesel power supply device is electrically connected to the intermediate DC circuit in sequence through a second switching unit and a second converter; the intermediate DC circuit is electrically connected to the input terminal of the locomotive traction device, the input terminal of the locomotive auxiliary device, and the input terminal of the train power supply system load; the dual-source locomotive has a contact wire power supply mode and a diesel power supply mode; characterized in that the method for switching the power system of the dual-source locomotive includes: When the first power supply mode switching signal is detected, the following steps A1-A3 are executed; Step A1: Adjust the output voltage of the first converter to the first voltage V1; Step A2: Close the second switch unit and start the internal combustion power supply device until the output voltage of the second converter reaches the second voltage V2 and the output current reaches the preset current threshold IA; V2 > V1; Step A3: Exit the overhead contact line power supply mode, so that the internal combustion power supply device can supply power independently; When a second power supply mode switching signal is detected, the following steps B1-B3 are executed; Step B1: Control the internal combustion power supply device until the output voltage of the second converter reaches the second voltage V2; Step B2: Connect the power supply line corresponding to the contact network power supply mode until the output voltage of the first converter reaches the third voltage V3; V3 > V2; Step B3: Exit the internal combustion power supply mode, so that the power supply is independent from the overhead contact line; The first power supply mode switching signal is a signal that moves from a energized section to a de-energized section, or a signal that switches the changeover switch from the contact network power supply position to the internal combustion engine power supply position; The second power supply mode switching signal is a signal that moves from a non-powered section to a powered section, or a signal that switches the changeover switch from the internal combustion power supply position to the contact network power supply position.

[0005] In the preferred embodiment, in the internal combustion power supply mode, the traction power P_r that the diesel engine can provide when it is in the nth gear is calculated using the following formula. 牵 : P_r 牵 =Pn*ρn*ρD-P 辅 -P 列 -P 裕 ; Where Pn is the output power of the diesel engine in the nth gear, ρn is the efficiency of the generator when the diesel engine is in the nth gear, ρD is the efficiency of the second converter, and P 辅 P is the power required for locomotive auxiliary devices. 列 P is the power required by the train's power supply system load. 裕 Allow for fluctuation margins in power control.

[0006] In a preferred embodiment, the internal combustion power supply device includes a diesel engine and a generator, wherein the diesel engine is electrically connected to a second converter via the generator; In the internal combustion power supply mode, determine the relationship between Pn*ρn*ρD and P. 牵 +P 辅 +P 列 +P 裕 The size relationship between them; If Pn*ρn*ρD>P 牵 +P 辅 +P 列 +P 裕 Then let P 牵 Increase to P 牵+ Thus, Pn*ρn*ρD=P 牵+ +P 辅 +P 列 +P 裕 ; If Pn*ρn*ρD<P 牵 +P 辅 +P 列 +P 裕 Then let P 牵Reduce to P 牵- Thus, Pn*ρn*ρD≥P 牵 +P 辅 +P 列 +P 裕 ; If Pn*ρn*ρD=P 牵 +P 辅 +P 列 +P 裕 Then let P 牵 Remain unchanged; Where Pt represents the currently provided traction power, Ptraction 牵+ To increase the traction power, P 牵- To reduce the traction power, Pn is the output power of the diesel engine in the nth gear, ρn is the generator efficiency when the diesel engine is in the nth gear, ρD is the efficiency of the second converter, and P 辅 P is the power required for locomotive auxiliary devices. 列 P is the power required by the train's power supply system load. 裕 Allow for fluctuation margins in power control.

[0007] Based on the same inventive concept, the present invention also provides a dual-source locomotive power system switching device, including a computer device or processor; characterized in that the computer device or processor is configured or programmed to perform the steps of the above-described dual-source locomotive power system switching method.

[0008] Based on the same inventive concept, the present invention also provides a dual-source locomotive, including the aforementioned dual-source locomotive power system switching device.

[0009] The advantages and positive effects of this invention are: (1) The locomotive achieves seamless switching between electric and diesel power supply modes in zero-speed or non-zero-speed states, and ensures uninterrupted power supply to locomotive auxiliary devices and train power supply system loads. (2) By setting up a power supply and diesel engine synchronous start-up mode (i.e., the contact network and generator supply power at the same time), the diesel engine can seamlessly supply power when the contact network power supply is interrupted under specific working conditions; (3) For internal combustion power supply mode, a matching and closed-loop control strategy for the power of traction, auxiliary and train power supply is proposed to solve the problem that the output power of diesel engine cannot be fully utilized. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a topology diagram of the locomotive main circuit transmission system according to an embodiment of the present invention; Figure 2 This is a flowchart of the closed-loop power control process for the internal combustion power supply mode according to an embodiment of the present invention.

[0012] In the above attached figures: 11. First converter; 12. Power receiving device; 13. Grid-side circuit; 14. Traction transformer; 101. First switching unit; 20. Internal combustion power supply unit; 21. Second converter; 22. Diesel engine; 23. Generator; 201. Second switch unit; 30. Overhead contact wire; 40. Intermediate DC circuit; 501. Locomotive auxiliary equipment; K1. First auxiliary contactor unit; 502. Train power supply system load; K2. Second auxiliary contactor unit; 51. First auxiliary inverter unit; 52. Second auxiliary inverter unit. Detailed Implementation

[0013] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0014] Example 1 Embodiment 1 of the present invention provides a method for switching the power system of a dual-source locomotive. The dual-source locomotive has a power receiving device 12, a diesel power supply device 20, and an intermediate DC circuit 40. The overhead contact line 30 is electrically connected to the intermediate DC circuit 40 in sequence through the power receiving device 12, a first switching unit 101, and a first converter 11. The diesel power supply device 20 is electrically connected to the intermediate DC circuit 40 in sequence through a second switching unit 201 and a second converter 21. The intermediate DC circuit 40 is electrically connected to the input terminal of the locomotive traction device, the input terminal of the locomotive auxiliary device 501, and the input terminal of the train power supply system load 502. The dual-source locomotive has an overhead contact line power supply mode and a diesel power supply mode. The method for switching the power system of the dual-source locomotive includes: When the first power supply mode switching signal is detected, the following steps A1-A3 are executed; Step A1: Adjust the output voltage of the first converter 11 to the first voltage V1; Step A2: Close the second switch unit 201 and start the internal combustion power supply device 20 until the output voltage of the second converter 21 reaches the second voltage V2 and the output current of the second converter 21 reaches the preset current threshold IA; V2 > V1; Step A3: Exit the overhead contact line power supply mode, so that the internal combustion power supply device 20 supplies power independently; When a second power supply mode switching signal is detected, the following steps B1-B3 are executed; Step B1: Control the internal combustion power supply device 20 until the output voltage of the second converter 21 reaches the second voltage V2; Step B2: Connect the power supply line corresponding to the contact network power supply mode until the output voltage of the first converter 11 reaches the third voltage V3; V3 > V2; Step B3: Exit the internal combustion power supply mode, so that the power supply is independent from the overhead contact line; The first power supply mode switching signal is a signal that moves from a energized section to a de-energized section, or a signal that switches the changeover switch from the contact network power supply position to the internal combustion engine power supply position; The second power supply mode switching signal is a signal that moves from a non-powered section to a powered section, or a signal that switches the changeover switch from the internal combustion power supply position to the contact network power supply position.

[0015] With the above settings, when a signal indicating a power outage is received and a switch to diesel power supply mode is required, the output voltage of the first converter 11 is first adjusted to the first voltage V1, and the output voltage of the second converter 21 is made to reach the second voltage V2, which is greater than V1. This allows the diesel power supply device to participate in supplying power to the intermediate DC circuit while maintaining power supply to the overhead contact line. When the output voltage of the second converter 21 reaches the second voltage V2, it indicates that the diesel power supply device has participated in supplying power to the intermediate DC circuit. When the output current of the second converter 21 is +IA (i.e., the current is the positive current flowing out of the second converter, and the current value is IA, where IA is preferably 20A), it indicates that the second converter has basically completed its takeover, and the power supply to the overhead contact line can be disconnected. With this setting, when a power supply switch is required, the overhead contact line continues to supply power during the startup of the diesel power supply device, meaning there is no need to interrupt the power supply to the locomotive auxiliary device 501 and the train power supply system load 502 (which can be simply referred to as the train power supply system load), ensuring vehicle comfort. Furthermore, considering that the output voltage of the first converter during normal operation of the overhead contact line is usually higher than the output voltage of the second converter in the internal combustion power supply path, in order to facilitate the internal combustion power supply path to participate in the power supply of the intermediate DC circuit without interrupting the overhead contact line power supply path, this invention adjusts the output voltage of the first converter 11 to a first voltage V1 before starting the internal combustion power supply device. This first voltage is less than the second voltage V2 (the voltage that the second converter connected to the output of the internal combustion power supply device can reach). This also facilitates the output of the second converter to participate in the power supply of the intermediate DC circuit after the internal combustion power supply device is started. Similarly, when a signal to enter an energized section is received, and it is necessary to switch to the overhead contact line power supply mode, the output voltage of the second converter 21 is first adjusted to the second voltage V2. After connecting the power supply line corresponding to the overhead contact line power supply mode, the first converter 11 outputs according to the rated voltage V3 (the third voltage), thus allowing the overhead contact line to participate in the power supply of the intermediate DC circuit while maintaining the internal combustion power supply. When the output voltage of the first converter 11 reaches the third voltage V3, it indicates that the contact network has taken over the power supply of the intermediate DC circuit, and the internal combustion engine power supply path can be disconnected at this time. With the above settings, if entering a de-energized section from an energized section, a first power supply mode switching signal can be received; if entering an energized section from a de-energized section, a second power supply mode switching signal can be received. Alternatively, the position of the changeover switch can be used to determine whether it is a first or second power supply mode switching signal.

[0016] The power receiving device 12 can be a pantograph. The first converter 11 can be a four-quadrant rectifier, and the second converter can be an uncontrolled rectifier; both are existing devices. The auxiliary devices in this invention are the auxiliary devices corresponding to the driver's cab, and the load of the train power supply system is all the electrical equipment on the passenger car.

[0017] In the preferred embodiment, the value range of V2-V1 is [20V, 120V], more preferably [50V, 90V]; the value range of V3-V2 is [80V, 180V], more preferably [110V, 150V]. In this embodiment, V2-V1 is 70V, and V3-V2 is 130V.

[0018] With the above settings, the voltage difference is set within a certain range, resulting in high efficiency and low impact of power supply path switching and adjustment.

[0019] In a preferred embodiment, when a first power supply mode switching signal is detected: before step A1, the method further includes: blocking the traction inverter; after step A3, the method further includes: releasing the block on the traction inverter. In a preferred embodiment, when a second power supply mode switching signal is detected: before step B1, the method further includes: blocking the traction inverter; after step B3, the method further includes: releasing the blockade of the traction inverter. The traction inverter is electrically connected between the intermediate DC circuit 40 and the locomotive traction device. The locomotive traction device can be as follows: Figure 1 The traction motors M1, M2, and M3 are shown.

[0020] More preferably, the operation of blocking the traction inverter is specifically: setting the output current of the traction inverter to 0; the specific operation of releasing the blockade of the traction inverter is: setting the output current of the traction inverter to the preset operating current.

[0021] The above settings allow for traction blocking during power supply switching, further ensuring the safety of the traction system.

[0022] In the above technical solution: The first power supply mode switching signal is a signal that moves from a energized section to a de-energized section, or a signal that switches the changeover switch from the contact network power supply position to the internal combustion engine power supply position; The second power supply mode switching signal is a signal that moves from a non-powered section to a powered section, or a signal that switches the changeover switch from the internal combustion power supply position to the contact wire power supply position; The selector switch is located in the driver's cab and has an internal combustion engine power supply position, a contact network power supply position, and a 0 position for disabling power supply.

[0023] In the above technical solution: The operation to exit the internal combustion power supply mode includes: turning off the internal combustion power supply device 20 and disconnecting the second switch unit 201; The operation of exiting the overhead contact line power supply mode includes: disconnecting the first switch unit 101, blocking the first converter 11, and performing the operation of disconnecting the main circuit breaker; The operation of connecting the power supply line corresponding to the contact network power supply mode includes: performing the operation of closing the main circuit breaker, closing the first switch unit 101, and releasing the blockade of the first converter 11; If the operation of exiting the overhead contact line power supply mode also includes lowering the pantograph, then the operation of connecting the power supply line corresponding to the overhead contact line power supply mode also includes raising the pantograph.

[0024] The power receiving device 12, the main circuit breaker (not shown in the figure), the traction transformer 14, and the first switching unit 101 are electrically connected in sequence. The operation of closing the first switching unit 101 may include closing the charging contactor KC and closing the short-circuit contactor KD.

[0025] If the first power supply mode switching signal is a phase-splitting signal (i.e., moving from a energized section to a de-energized section), then the operation to exit the overhead contact line power supply mode does not require lowering the pantograph. If the subsequent de-energized section is at the end of the line (e.g., entering a workshop), then the operation to exit the overhead contact line power supply mode may include lowering the pantograph. Whether or not to lower the pantograph during the operation to exit the overhead contact line power supply mode can be determined by actual requirements.

[0026] The operation of blocking the first converter 11 includes: turning off the pulses of each switching transistor in the first converter 11, that is, each switching transistor stops outputting; The operation to unlock the first converter 11 includes: activating the pulses of each switching transistor in the first converter 11 (i.e., enabling control of each switching transistor). This controls the semiconductor power transistor pulses, thereby adjusting the output voltage of the first converter 11 to a preset operating voltage.

[0027] In the above technical solution, the specific method for controlling the internal combustion power supply device 20 in step A2 is as follows: control the speed of the diesel engine according to the preset diesel engine gear, wherein the output voltage of the second converter 21 corresponding to the preset diesel engine gear is the second voltage V2; detect the output voltage and output current of the second converter; if the output voltage of the second converter 21 reaches the second voltage V2 and the output current of the second converter 21 reaches the preset current threshold IA, it is determined that the second converter 21 has completed the takeover, and the operation of exiting the contact network power supply mode in step A3 can be executed.

[0028] In step A3, when the internal combustion power supply device 20 supplies power independently, the internal combustion power supply device 20 is controlled according to the required power (i.e., the required power of the traction system, the required power of the locomotive auxiliary device 501, and the required power of the train power supply system load 502).

[0029] According to this setting, the diesel engine power supply device 20 can be controlled based on the power requirements of the traction system, the locomotive auxiliary device 501, and the train power supply system load 502. For example, when the power requirement is high, the diesel engine is set to a higher gear; when the power requirement is low, the diesel engine is set to a lower gear.

[0030] The third voltage V3 is the constant output voltage of the first converter 11 when the contact network 30 is independently powered.

[0031] The internal combustion power supply device 20 includes a diesel engine 22 and a generator 23. The diesel engine 22 is electrically connected to the second converter 21 in sequence through the generator 23 and the second switching unit 201.

[0032] The first switching unit 101 includes a charging contactor KC and a shorting contactor KD; the series circuit formed by the charging contactor KC and the charging resistor RC is connected in parallel with the charging contactor KC to form a parallel circuit; the parallel circuit is electrically connected between the power receiving device 12 and the first converter 11.

[0033] The intermediate DC circuit 40 includes a capacitor; The positive output terminal of the first converter 11 and the positive output terminal of the second converter 21 are both electrically connected to one end of the capacitor; The negative output terminal of the first converter 11 and the negative output terminal of the second converter 21 are both electrically connected to the other end of the capacitor; One end and the other end of the capacitor respectively form the positive output terminal and the negative output terminal of the intermediate DC circuit 40.

[0034] The first power supply mode switching signal is an over-phase signal (also known as an over-phase warning signal); the second power supply mode switching signal is an entry into the energized section signal.

[0035] In a preferred embodiment, the internal combustion power supply device 20 includes a diesel engine 22 and a generator 23, wherein the diesel engine 22 is electrically connected to the second converter 21 in sequence through the generator 23 and the second switching unit 201. In internal combustion engine power supply mode, the traction power P_r that the diesel engine can provide when it is in the nth gear is calculated using the following formula. 牵 : P_r 牵 =Pn*ρn*ρD-P 辅 -P 列 -P 裕 ; Where Pn is the output power of the diesel engine 22 in the nth gear, ρn is the efficiency of the generator 23 when the diesel engine 22 is in the nth gear, ρD is the efficiency of the second converter 21, and P 辅For the power required by locomotive auxiliary device 501, P 列 P is the power required by the train's power supply system load 502. 裕 A margin of error is reserved for power control. According to this preferred scheme, the available traction power is directly calculated.

[0036] By calculating the available traction power, the diesel engine output power was fully utilized while ensuring power supply to the locomotive auxiliary device 501 and the train power supply system load 502 and ensuring power fluctuation.

[0037] The internal combustion power supply device 20 includes a diesel engine 22 and a generator 23. The diesel engine 22 is electrically connected to the second converter 21 through the generator 23. like Figure 2 As shown, in the preferred scheme, in the internal combustion power supply mode, the relationship between Pn*ρn*ρD and P is determined. 牵 +P 辅 +P 列 +P 裕 The size relationship between them; If Pn*ρn*ρD>P 牵 +P 辅 +P 列 +P 裕 Then let P 牵 Increase to P 牵+ Thus, Pn*ρn*ρD=P 牵+ +P 辅 +P 列 +P 裕 ; If Pn*ρn*ρD<P 牵 +P 辅 +P 列 +P 裕 Then let P 牵 Reduce to P 牵- Thus, Pn*ρn*ρD=P 牵 +P 辅 +P 列 +P 裕 ; If Pn*ρn*ρD=P 牵 +P 辅 +P 列 +P 裕 This keeps the traction power at P. 牵 ; Where Ptraction represents the current traction power, Ptraction 牵+ To increase the traction power, P 牵-To reduce the traction power, Pn is the output power of the diesel engine 22 in the nth gear, ρn is the efficiency of the generator 23 when the diesel engine 22 is in the nth gear, ρD is the efficiency of the second converter 21, and P 辅 For the power required by locomotive auxiliary device 501, P 列 P is the power required by the train's power supply system load 502. 裕 A margin of error is reserved for power control. According to this preferred scheme, the traction power is adjusted based on the available traction power.

[0038] Through the above adjustments, the diesel engine output power is fully utilized while ensuring power supply to the locomotive auxiliary device 501 and the train power supply system load 502 and ensuring power fluctuation.

[0039] Based on the same inventive concept, the present invention provides a dual-source locomotive power system switching device, including a computer device or processor; the computer device or processor is configured or programmed to perform the steps of the dual-source locomotive power system switching method.

[0040] Based on the same inventive concept, the present invention provides a dual-source locomotive, including the aforementioned dual-source locomotive power system switching device.

[0041] The first traction motor M1, the second traction motor M2, and the third traction motor M3 are electrically connected to the intermediate DC circuit 40 through their respective traction inverters.

[0042] The first voltage V1 has a value range of 1550V-1650V, preferably 1600V; the value range of the second voltage V2 can be determined according to the gear of the diesel engine, etc.; and the value of the third voltage V3 can generally be 1800V or 1850V.

[0043] This invention designs a dual-power locomotive transmission main circuit and provides a power system switching and power closed-loop control strategy and method: On electrified lines, the locomotive uses overhead contact line power supply for traction, with power supplied through the contact line, then stepped down by the pantograph and other grid-side circuits and traction transformers before being supplied to the converter system. On non-electrified lines, the locomotive uses diesel generator power supply for traction, with a high-power diesel engine driving a generator to generate electricity. The main circuit breaker can be installed, for example, on the grid-side circuit.

[0044] When switching from an electrified line to a non-electrified line, the locomotive can switch from electric power supply mode to diesel power supply mode without stopping by using the power mode conversion switch. During the conversion, the diesel engine is manually started and the excitation is engaged. After the conversion is completed, the locomotive automatically disconnects the main circuit breaker and lowers the pantograph. After completion, the driver can issue a traction command again to resume normal operation.

[0045] When switching from a non-electrified line to an electrified line, the locomotive can switch from diesel power supply mode to electric power supply mode without stopping by using the power mode conversion switch. During the conversion, the pantograph is manually raised and the main circuit breaker is closed. After the conversion is completed, the locomotive automatically cuts off the excitation and stops the diesel engine. After completion, the driver can give the traction command again to resume normal operation.

[0046] In this embodiment, during the switching period, the locomotive traction is blocked, but the locomotive auxiliary device 501 and the train power supply system load 502 are powered without interruption. This invention realizes the switching between the overhead contact line power system and the internal combustion engine power system. The overhead contact line power system includes an overhead contact line 30, a first converter 11, and various components connecting the two; the internal combustion engine power system includes a diesel engine 22, a second converter 21, and various components connecting the two.

[0047] In special operating conditions, such as when on-site operations require uninterrupted power supply to the auxiliary and train power supply system load 502 during phase transitions on electrified lines, the diesel engine is required to provide power. To ensure smooth takeover of diesel engine power supply under this condition, a hybrid electric and diesel power supply mode needs to be designed (e.g., "forced diesel power system switching mode under catenary power supply"). In this mode, the locomotive can be powered by the pantograph, while the diesel engine is in a hot standby state. When the locomotive detects a certain warning signal (e.g., a phase transition warning signal), the locomotive begins traction blocking. The output voltage of the four-quadrant rectifier (i.e., the first converter) drops to the output voltage of the second rectifier (connected to the generator output), and the output current of the first converter is gradually reduced to 0, switching to diesel engine power supply. After the phase transition is completed and the main circuit breaker is closed, the four-quadrant rectifier starts working and outputs according to the rated operating voltage V3, raising the intermediate voltage, and the diesel engine power supply is discontinued.

[0048] For the internal combustion power supply mode, since the diesel engine speed is only fixed, that is, the output power of the internal combustion power system is constant, the traction output closed-loop control strategy is formed by comprehensively calculating the diesel engine output parameters, generator efficiency, auxiliary and train power supply system load consumption. Compared with the original problem of the excess power being consumed by the chopper resistor and causing a large energy waste, this invention maximizes the energy utilization rate of the internal combustion system.

[0049] Locomotive rotation system topology as follows Figure 1 . Figure 1 This is the main circuit topology diagram of an internally integrated dual-source locomotive, which has two functional modes: power supply via pantograph and power supply via diesel engine-driven generator. All energy is concentrated in the locomotive's intermediate DC circuit. Figure 2 The power closed-loop control flowchart is shown in the internal combustion engine power supply mode.

[0050] like Figure 1As shown, the locomotive auxiliary device 501 is a load installed on the locomotive head car and powered by an auxiliary converter. Examples include: a locomotive traction cooling system, an air supply system, a cooling unit (for cooling the traction transformer and diesel engine), and driver / passenger loads. For instance, the locomotive auxiliary device includes a locomotive traction fan, a diesel engine cooling fan (VVVF) (which can also be used to cool the traction transformer), and may also include locomotive pumps, compressors, and driver / passenger loads (CVCF). Each device in the locomotive auxiliary device 501 can be electrically connected to an intermediate DC circuit via a high-frequency auxiliary inverter. For example, the first auxiliary inverter unit 51 can consist of two or more auxiliary inverters, and the first auxiliary contactor unit K1 can consist of two or more auxiliary contactors. The number of auxiliary inverters in the first auxiliary inverter unit 51 is the same as the number of auxiliary contactors in the first auxiliary contactor unit K1. The locomotive auxiliary device can be divided into multiple corresponding parts, each part being sequentially connected to the circuit via a corresponding auxiliary contactor and a corresponding auxiliary inverter.

[0051] The train power supply system load 502 can be electrically connected to the intermediate DC circuit 40 in sequence through the second auxiliary contactor unit K2 and the second auxiliary inverter unit 52. The train power supply system load 502 is a load installed in the rear passenger car, such as passenger car loads such as car air conditioning, ventilation, lighting, and passenger sockets.

[0052] In this invention, the locomotive is designed with two power supply modes: overhead contact line power supply mode and internal combustion engine power supply mode.

[0053] (1) Schema definition: Each control panel is equipped with a power mode switch, which has "electric," "0," and "diesel" positions. The switch is only effective when operated from the driver's cab at the occupied end. During the internal power switching process, the locomotive traction is blocked, but the auxiliary machinery and train power supply systems remain uninterrupted.

[0054] Overhead contact line power supply mode: ① Power is supplied to the loads of traction, auxiliary and train power supply systems through pantograph current collection; ② Diesel engines are prohibited from starting and excitation is prohibited.

[0055] Position 0: ① In the locomotive's no-power mode, it is prohibited to raise the pantograph, close the main circuit breaker, start the diesel engine, or engage the excitation; ② Traction is prohibited (except for EMUs in the depot), and the train's power supply system is prohibited from outputting load.

[0056] Internal combustion power supply mode: ① The main generator is driven by a diesel engine to supply power to the loads of the traction, auxiliary and train power supply systems; ② Raising the pantograph and closing the main circuit breaker are prohibited.

[0057] (2) Mode switching control strategy: The locomotive can switch between overhead contact line power supply mode and diesel power supply mode at zero speed or non-zero speed via a "power mode" selection switch. Power mode switching is only effective on the main control terminal and requires the driver's controller handle to be returned to the maximum zero position. The specific switching logic is shown in Table 1.

[0058] Table 1. Switching logic for different switching methods (3) Integrated control strategy for electric and internal combustion power supply: To ensure uninterrupted power supply to the train's power supply system load and auxiliary systems under specific locomotive operating conditions (such as phase transitions), the DDU is equipped with a "forced switching of the diesel system under catenary power supply mode" function, as detailed below: During normal operation, the excitation is maintained (except when manually disconnected), the four-quadrant rectifier is controlled at V3 (e.g., 1800V), and the diesel engine output voltage is controlled at V2 (e.g., 1670V, fixed logic gear speed output). When a warning signal is detected (e.g., over-phase warning signal), the locomotive traction and electrical systems are locked. The four-quadrant rectifier controls the intermediate voltage of the traction system to decrease from V3 to V2, while the diesel engine control voltage remains at V2. The four-quadrant rectifier limits the output current until it decreases to 0. After a specific operating condition signal is removed (e.g., over-phase signal removal), if the main circuit breaker closes for more than 2 seconds, the four-quadrant rectifier controls the intermediate voltage to V, and the locomotive operates in the contact network power supply mode, with the excitation maintained but no energy output.

[0059] (4) Power closed-loop control strategy under internal combustion power supply mode Because the power grid has a large capacity, it can draw the required power from the grid according to the load demand. Therefore, there is no power closed-loop control in the overhead contact line power supply mode.

[0060] In diesel-electric power supply mode, the driver and crew issue traction level commands based on the track conditions. After receiving the level command, the locomotive controls the diesel engine to the corresponding speed to drive the generator. The locomotive adjusts the output power P of the diesel engine according to the different gears. n and the generator efficiency ρ at different gears n Calculate the generator output power P 发 The power PDC of the intermediate DC circuit is calculated by combining the efficiency ρD of the uncontrolled rectifier (i.e., the second converter). In this embodiment, PDC = Pn * ρ ...D; the power PDC consumed by the locomotive auxiliary device 501 is collected by sensors. 辅 and the power consumption P of the train power supply system load 列 Power control reserves a fluctuation margin P 裕 (e.g., 5kW), the available traction power is Pr 牵 =Pn*ρn*ρD-P 辅 -P 列 -P裕， This control strategy and method improves the power utilization rate of diesel engines at various speeds.

[0061] In this system, the driver generates a gear signal by operating the driver's controller, and the locomotive network control system assigns the appropriate gear signal to the diesel engine based on the magnitude of the gear signal; this is existing technology. The increase / decrease in traction power needs to be considered based on power fluctuations, such as fluctuations in auxiliary loads.

[0062] Because auxiliary loads may experience sudden increases and decreases (while the train's power supply system load remains essentially constant), constantly adjusting the traction power based on changes in auxiliary loads would affect locomotive stability. In this invention, the control of traction power is delayed by a certain time ΔT compared to the acquisition of auxiliary load power. Preferably, ΔT is 2-5 seconds, more preferably 3 seconds.

[0063] Example 2 The difference between Embodiment 2 and Embodiment 1 is that when the first power supply mode switching signal is detected, the traction inverter does not need to be blocked before step A1; when the second power supply mode switching signal is detected, the traction inverter does not need to be blocked before step B1.

[0064] In this embodiment 2, power can be continuously supplied to the traction device during the power supply switching process.

[0065] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0066] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention should still fall within the scope of the present invention. After reading this invention, modifications of various equivalent forms of the present invention by those skilled in the art fall within the scope defined by the appended claims. Unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

Claims

1. A method for switching the power system of a dual-source locomotive, wherein the dual-source locomotive has a power receiving device (12), an internal combustion power supply device (20), and an intermediate DC circuit (40); the contact wire (30) is electrically connected to the intermediate DC circuit (40) in sequence through the power receiving device (12), a first switching unit (101), and a first converter (11); the internal combustion power supply device (20) is electrically connected to the intermediate DC circuit (40) in sequence through a second switching unit (201) and a second converter (21); the intermediate DC circuit (40) is electrically connected to the input end of the locomotive traction device, the input end of the locomotive auxiliary device (501), and the input end of the train power supply system load (502); The dual-source locomotive has both overhead contact line power supply mode and internal combustion engine power supply mode; its characteristic is that... The method for switching the dual-source locomotive power system includes: When the first power supply mode switching signal is detected, the following steps A1-A3 are executed; Step A1: Adjust the output voltage of the first converter (11) to the first voltage V1; Step A2: Close the second switch unit (201), start the internal combustion power supply device (20) until the output voltage of the second converter (21) reaches the second voltage V2 and the output current reaches the preset current threshold IA; V2 > V1; Step A3: Exit the overhead contact line power supply mode, so that the internal combustion power supply device (20) supplies power independently; When a second power supply mode switching signal is detected, the following steps B1-B3 are executed; Step B1: Control the internal combustion power supply device (20) until the output voltage of the second converter (21) reaches the second voltage V2; Step B2: Connect the power supply line corresponding to the contact network power supply mode until the output voltage of the first converter (11) reaches the third voltage V3; V3 > V2; Step B3: Exit the internal combustion power supply mode, so that the power supply is independent from the overhead contact line; The first power supply mode switching signal is a signal that moves from a energized section to a de-energized section, or a signal that switches the changeover switch from the contact network power supply position to the internal combustion engine power supply position; The second power supply mode switching signal is a signal that moves from a non-powered section to a powered section, or a signal that switches the changeover switch from the internal combustion power supply position to the contact network power supply position.

2. The method for switching between dual-source locomotive power systems according to claim 1, characterized in that, The value range of V2-V1 is [20V, 120V]; the value range of V3-V2 is [80V, 180V].

3. The method for switching between dual-source locomotive power systems according to claim 1, characterized in that, When a first power supply mode switching signal is detected: before step A1, the method further includes: blocking the traction inverter; after step A3, the method further includes: releasing the block on the traction inverter; When a second power supply mode switching signal is detected: before step B1, the method further includes: blocking the traction inverter; after step B3, the method further includes: releasing the block on the traction inverter. The traction inverter is electrically connected between the intermediate DC circuit (40) and the locomotive traction device. Preferably, the operation of blocking the traction inverter is as follows: setting the output current of the traction inverter to 0; the operation of releasing the blockade of the traction inverter is as follows: setting the output current of the traction inverter to the preset operating current.

4. The method for switching between dual-source locomotive power systems according to claim 1, characterized in that, The selector switch is located in the driver's cab and has an internal combustion engine power supply position, a contact network power supply position, and a 0 position for disabling power supply.

5. The method for switching between dual-source locomotive power systems according to claim 1, characterized in that, The operation to exit the internal combustion power supply mode includes: turning off the internal combustion power supply device (20) and disconnecting the second switch unit (201). The operation of exiting the overhead contact line power supply mode includes: disconnecting the first switch unit (101), blocking the first converter (11), and performing the operation of disconnecting the main circuit breaker; The operation of connecting the power supply line corresponding to the contact network power supply mode includes: performing the operation of closing the main circuit breaker, closing the first switch unit (101), and releasing the blockade of the first converter (11); If the operation of exiting the overhead contact line power supply mode also includes lowering the pantograph, then the operation of connecting the power supply line corresponding to the overhead contact line power supply mode also includes raising the pantograph.

6. The method for switching between dual-source locomotive power systems according to claim 1, characterized in that, The operation of blocking the first converter (11) includes: shutting off the pulses of each switching transistor in the first converter (11); The operation to release the blockade of the first converter (11) includes: turning on the pulses of each switching transistor in the first converter (11).

7. The method for switching between dual-source locomotive power systems according to claim 1, characterized in that, In step A3, when the internal combustion power supply device (20) supplies power independently, the internal combustion power supply device (20) is controlled according to the required power.

8. The method for switching a dual-source locomotive power system according to any one of claims 1-7, characterized in that, The third voltage V3 is the constant output voltage of the first converter (11) when the contact network (30) is independently powered.

9. The method for switching a dual-source locomotive power system according to any one of claims 1-7, characterized in that, The first switching unit (101) includes a charging contactor KC and a short-circuit contactor KD; the series circuit formed by the charging contactor KC and the charging resistor RC is connected in parallel with the charging contactor KC to form a parallel circuit; the parallel circuit is electrically connected between the power receiving device (12) and the first converter (11).

10. The method for switching a dual-source locomotive power system according to any one of claims 1-7, characterized in that: The intermediate DC circuit (40) includes a capacitor; The positive output terminal of the first converter (11) and the positive output terminal of the second converter (21) are both electrically connected to one end of the capacitor; The negative output terminal of the first converter (11) and the negative output terminal of the second converter (21) are both electrically connected to the other end of the capacitor; One end and the other end of the capacitor respectively form the positive output terminal and the negative output terminal of the intermediate DC circuit (40).

11. The method for switching a dual-source locomotive power system according to any one of claims 1-7, characterized in that, The internal combustion power supply device (20) includes a diesel engine (22) and a generator (23). The diesel engine (22) is electrically connected to the second converter (21) in sequence through the generator (23) and the second switch unit (201). In internal combustion engine power supply mode, the traction power P_r that the diesel engine can provide when it is in the nth gear is calculated using the following formula. 牵 : P_r 牵 =Pn*ρn*ρD-P 辅 -P 列 -P 裕 ; Where Pn is the output power of the diesel engine (22) in the nth gear, ρn is the efficiency of the generator (23) when the diesel engine (22) is in the nth gear, ρD is the efficiency of the second converter (21), and P 辅 For the power required by the locomotive auxiliary device (501), P 列 P is the power required by the train power supply system load (502). 裕 Allow for fluctuation margins in power control.

12. The method for switching a dual-source locomotive power system according to any one of claims 1-7, characterized in that, The internal combustion power supply device (20) includes a diesel engine (22) and a generator (23). The diesel engine (22) is electrically connected to the second converter (21) in sequence through the generator (23) and the second switch unit (201). In the internal combustion power supply mode, determine the relationship between Pn*ρn*ρD and P. 牵 +P 辅 +P 列 +P 裕 The size relationship between them; If Pn*ρn*ρD>P 牵 +P 辅 +P 列 +P 裕 Then let P 牵 Increase to P 牵+ Thus, Pn*ρn*ρD=P 牵+ +P 辅 +P 列 +P 裕 ; If Pn*ρn*ρD<P 牵 +P 辅 +P 列 +P 裕 Then let P 牵 Reduce to P 牵- Thus, Pn*ρn*ρD=P 牵 +P 辅 +P 列 +P 裕 ; If Pn*ρn*ρD=P 牵 +P 辅 +P 列 +P 裕 This keeps the traction power at P. 牵 ; Among them, P 牵 For the current traction power, P 牵+ To increase the traction power, P 牵- To reduce the traction power, Pn is the output power of the diesel engine (22) in the nth gear, ρn is the efficiency of the generator (23) when the diesel engine (22) is in the nth gear, ρD is the efficiency of the second converter (21), and P 辅 For the power required by the locomotive auxiliary device (501), P 列 P is the power required by the train power supply system load (502). 裕 Allow for fluctuation margins in power control.

13. A dual-source locomotive power system switching device, comprising computer equipment or a processor; characterized in that... The computer device or processor is configured or programmed to perform the steps of the dual-source locomotive power system switching method according to any one of claims 1-12.

14. A dual-source locomotive, characterized in that... It includes the dual-source locomotive power system switching device as described in claim 13.

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